1,6

Erdos proved that between any n > 7 and its double there are always at least two primes, one of form 4n+1 and one of form 4n+3.

B. Schechter, "My Brain is Open: The Mathematical Journeys of Paul ErdÅ‘s," Simon & Schuster, New York, 1998, p. 62.

Table of n, a(n) for n=1..102.

Cf. A035250, A087010, A087012.

Sequence in context: A025885 A198337 A206483 * A294602 A000174 A156268

Adjacent sequences: A087008 A087009 A087010 * A087012 A087013 A087014

nonn

Jason Earls, Jul 30 2003

approved